Boiler



Nov. 17, 1931. A, WEIGEL 1,832,071

BOILER Filed Aug. 29, 1929 2 Sheets-Sheet l 04 a; a a

IN VENT OR BY W6:

WORNEYS Nov. 17, 1931. c, WEIGEL 1,832,071

BOILER Filed Aug. 29. 1929 2 Sheets-Sheet 2 INVENTOR BY W5. W WFMM ATTORNEYS Patented Nov. 17, 1931 entree srarss PATENTOFFECE ALBERT C. WEIGEL, OF EAST ORANGE NEW JERSEY, ASSIGNOR T INTERNATIONAL COMBUSTION ENGINEERING OF DELAWARE CORPORATION, OF NEW YORK, Y., A CORPORATION BOILER Application filed August 29, 1929. Serial No. 389,111.

This invention relates to improvements in boilers of the cross drum type having vertically spaced banks of substantially horizontal tubes connected at their ends into front and rear headers.

One of the primary objects of my invention is to increase the effectiveness of the low.- er bank or section of such boilers.

More specifically stated it is an object of my invention to provide an improved arrangement of the tubes of the lower or dropheader sections of boilers of the class described whereby the velocity of the .gases across the upper rows of tubes of theglower 5 section may be considerably reducedbelow the velocity across the lower rows of tubes, thus reducing the average velocity of gases entering the boiler and thereby increasing the eflectiveness of the lower section or bank.

.How the foregoing, together .with such other objects and advantages, as may hereinafter appear, or are incident to my invention are realized is illustrated in preferred form in the accompanying drawings, wherein V Fig. 1 is a sectional side elevation of a boiler of the cross drum type embodying my invention.

Fig. 2 is a fragmentary crosssection taken on the line 22 of Fig. 1. and

Figs. 3, 4. 5 and 6 are enlarged fra Qmentary sectional views illustrating; modified arranrzements of the tubes of the lower section of the boiler.

The boiler comprises in general a steam and water drum (1. an upper section or mam bank of substantially horizontal boiler tubes Z). and a lower bank of substantially horizontal boiler tubes 0, commonly known as the 0 drop-header section of the boiler.

The main bank 72 is composed of a multipli city of boiler tubes inclined somewhat from the horizontal and arranged in a plurality of staggered rows. the tubes of each row being relatively closely spaced. say. for example, on 7 inch centers with 4 inch tubes and the rows also being relativelyclosely spaced. say, for example, on 6 inch centers. of the bank are connected at one end into the front headers 3 and at their other ends into The tubes the rear headers 4, which headers may be of the sinuous type.

A plurality of downcomer tubes 5 lead from the water space of the drum a to the front headers 3 and a plurality of rows of tubes 6 lead from the rear headers 4- to the steam space of the drum a to deliver steam generated in the boiler to the drum. The drum is provided with a steam outlet 7 and may'have a feed water inlet located at any suitable point.

The lower bank or dropsheader section 0 of'the boiler is composed of a plurality of boiler tubes inclined similarly to those of the main bank and arranged in a plurality of rows. The tubes of the rows are connected at one end into the front drop-headers 8 and at their other ends into the rear dropheaders 9, which drop-headers may be of the same form as the headers of the main bank. Tubes 10 connect the front headers 3 and 8 and tubes l1 connect the rear headers tand 9.

I am aware that it has been proposed heretofore to provide drop-header sections for boilers, but it has been customary to arrange are relatively closely spaced as are also the rows themselves. The tubes of the two lower rows 1% and 15 and ofthe two upper rows 16 and 17 are much more widely spaced apart. Also the space between the rows 14,

15 and 16, 17, and the distance these rows are spaced above and'belowthe intermediate rows 12 and 13 is much greater thanthe space between the rows 12 and 13.

By way of example it may be assumed that the tubes of the rows 12 and 13 are spaced on 7 inch centers and those of the rows, 14:, 15, 16 and 17 on 1 1 inch centers. The vertical. spacing of the rows 12 and 13 may be assumed to be 6%; inches and that of remaining rows 12% inches. It is pointed out, however, that in some instances it may be desirable to arrange all of the lower rows in close spacing.

In boilers of the type herein involved it is standard practice to arrange the tubes in rows which are spaced approximately inches apart and to locate the tubes on approx mately 7 inch centers in the "rows. and it will be seen, therefore, that I may obtain my novel arrangement of tubes while still employing standard headers arranged in the usual manner, in which case I omit. the usual rows of tubes between the rows l l, '15 and 12, and between the rows 13. 16 .and .17. La the rows 14, 15, 16 and I7 I omit alternate tubes so that the spacing of these'tubes w ll be twice the standard spacing. The tube holes in the headers where tubes have been omitted may be plugged if headers having standard spaced holes are employed. ever, headers having blank spaces where tubes are to be omitted may be employed.

, A superheater .18 may be located. in the space 19 between the upper and lower banks and suitable bafiiing such as indicated at 20, 21 and 22 maybe provided. The products .of combustion leaving the combustion chamber 23 pass upwardly over and among the tubes of the lower bank 0, then rise through the pass 24. then pass downwardly through the ass 25, then up through the pass 26 and finally pass to the otftake .27.

The combustion chamber may be fired in any suitable manner. althou ghI prefer to employ pulver zed fuel, and the chamber may be provided with steam evaporating surfaces, such as water tubes 28 and 29, 'ar range to line walls of the chamber.

In Fig. 3 I have shown a modification of the invention in which the space between the four upper rows of tubes 12a, 13a. 16a and 17a. is the same, but it is to be noted that alternate tubes are omitted .in the two upper rows 16a and 1 a. 1

In the modification illustrated in Fig. 4:

the space between the two upperrows of tubes 16b and 17b is the same as the space between the two intermediate rows 12?) and 1 37), but the space between'the rows .13?) and 16b is considerably greater. Alternate tubes are omi ted in the two upper rows 16?) and 1719.

In Fig. 5 a modification is illustrated in which the rows 120 13c and 160 are of like spacing, while the spacing between the rows 161i and 170 is considerably greater. Here, again. alternate tubes of the upper rews 16c and 170 are omitted. i

The arrangement of the two lower rows of Figs. 3, a and 5 maybe the same as that of Figs. 1 and 2.

In Fig. 6 I have illustrated a. modification in which five rows of tubes are employed.

How-

The four upper rows of tubes 12d, 13d, 16d and 17 (Z may be arranged in accordance with any of the forms above described and as illustrated the arrangement is the same as Fig. 2. The bottom row of tubes lid is spaced below the row 12d a distance approximately equal to twice the spacing of the rows 12d and 13d. The tubes of the bottom row are spaced on close centers corresponding to the spacing oft-he tubes of the rows 12d and 180 From the foregoing it Vlillbfi seen that I have provided an arrangement in which the velocity of the gases across the upper rows of tubes of the drop header section 0 will be considerably reduced over standard practice, thereby making the tubes of the section more .eifective; Furthermore, the average velocity ,of gases entering the boiler is reduced- In consequence, among other things, the drop header bank is made more effective throughout its length.

The arrangement is particularly advantageous in boilers having baffling of the general arrangement illustrated in the drawings, for the .reason that, without provision to the contrary, the point of maximum resistance to gasflow in such boilers is at the bottom of the upright bafiie 21 due to the fact that the hotgas must pass through an area approximately equal to one-half the length of tubes and of-a width equal to the space between the tubes '(say three inches in standard practice) times the number of sections.

Through the practice of my invention this area maybe increased as much as 66 for I have cut down thenumber of tubes in the upper rows of the drop header section. By spreading these upper rows vertically, suiticient room is left for the eases to enter the freer space along practically the full length of the tubes that are close together and then part of the gases can run parallel to the tubes and freely enter the space immediately below the superheater;

The arrangement of the lower rows of tubes prevents choking or substantial restriction the gas passages.

.1. In a boiler having a main section of boiler tubes and a drop-header sectionof boiler tubes, the combination of upper and lower rows ofspaced boiler tubes in the drop header section, the'upper rows being spaced more widely apart than lower rows and the spacing of the tubes of the upper rows being greater than the spacing of the tubes of lower rows.

2. A boiler including vertically spaced banks of substantially horizontal water tubes and their headers, the lower bank having a plurality of rows of boiler tubes, at least two lower rows of which are closely spaced and composed of a plurality of closely spaced tubes and at least the two top rows of which are relatively widely spaced apart and composed of a plurality of relatively widely spaced tubes, and a super-heater located in the space between the banks of tubes.

3. A boiler including vertically spaced banks of substantially horizontal water tubes and their headers, the lower bank having a plurality of rows of boiler tubes arranged in lower, intermediate and upper groups, the

tubes of the intermediate group being relatively closely spaced and the tubes of the lower and upper group being relatively widely spaced.

4. A boiler including vertically spaced banks of substantially horizontal water tubes and their headers, the lower bank having upper and lower rows of spaced boiler tubes, the upper rows being spaced more widely apart than lower rows and the spacing of the tubes of the upper rows being greater than the spacing of the tubes of lower rows.

In testimony whereof I have hereunto signed my name.

' ALBERT C. WEIGEL. 

